In
a large pot, heat oil over medium heat and saute onion for about 2
minutes, until soft. Stir in tomatoes and ginger, cooking an addition 3
minutes. Stir in turmeric, cumin, coriander, cinnamon, cayenne and
salt and cook for 2 minutes, tasting to make sure its to your liking.

Next
add the sweet potatoes, broth and lentils. Bring soup to a boil then
reduce heat and cover, allowing to simmer for about 30 minutes. Then
add spinach (or kale) and simmer for an additional 10 minutes. Enjoy!